days_from_date.py

import re  # regular expressions
import calendar  # module of python to provide useful fucntions related to calendar
import datetime  # module of python to get the date and time
import tkinter as tk

root = tk.Tk()
root.geometry("400x250+50+50")
user_input1 = tk.StringVar()


def process_date(user_input):
    user_input = re.sub(r"/", " ", user_input)  # substitute / with space
    user_input = re.sub(r"-", " ", user_input)  # substitute - with space
    return user_input


def find_day(date):
    born = datetime.datetime.strptime(
        date, "%d %m %Y"
    ).weekday()  # this statement returns an integer corresponding to the day of the week
    return calendar.day_name[
        born
    ]  # this statement returns the corresponding day name to the integer generated in the previous statement


# To get the input from the user
# User may type 1/2/1999 or 1-2-1999
# To overcome those we have to process user input and make it standard to accept as defined by  calender and time module
def printt():
    user_input = user_input1.get()
    date = process_date(user_input)
    c = "Day on " + user_input + "  is " + find_day(date)
    label2 = tk.Label(root, text=c, font=("Times new roman", 20), fg="black").place(
        x=20, y=200
    )


lbl = tk.Label(root, text="Date --", font=("Ubuntu", 20), fg="black").place(
    x=0, y=0.1, height=60, width=150
)
lbl1 = tk.Label(root, text="(DD/MM/YYYY)", font=("Ubuntu", 15), fg="Gray").place(
    x=120, y=0.1, height=60, width=150
)
but = tk.Button(
    root,
    text="Check",
    command=printt,
    cursor="hand2",
    font=("Times new roman", 40),
    fg="white",
    bg="black",
).place(x=50, y=130, height=50, width=300)
Date = tk.Entry(
    root, font=("Times new roman", 20), textvariable=user_input1, bg="white", fg="black"
).place(x=30, y=50, height=40, width=340)

root.mainloop()